1. Field of the Invention
The present invention relates to a one-pack type dental adhesive composition which can exhibit excellent adhesion to any material, for example, dental ceramics, organic composites containing inorganic compounds (hereinafter referred to as “composite materials”), noble and non-noble metals for use in dental procedures, and which also exhibits excellent storage stability.
2. Description of the Related Art
Composite materials of inorganic materials and inorganic/organic composite materials are often used as dental restorative materials. Typical examples thereof include dental porcelain (containing silicon dioxide as a main component), alumina core, zirconia core and composite. Composites are prepared by mixing an inorganic powder with a resin and the resultant mixture is in the form of a paste. Metallic materials are also used.
There have hitherto been made a trial of improving surface adhesion using silane coupling agents and a trial of improving surface adhesion using acid monomers. It is known that the silane coupling agents improve adhesion to materials having silicon dioxide as a main component. The acid monomers improve adhesion to materials having alumina or zirconia as a main component.
Among metals used in dental procedures (hereafter “dental metals”), non-noble metal alloys contain nickel, chromium, copper and titanium as main components. Japanese Examined Patent Publication (Kokoku) No. 60-42222 discloses the use of 4-acryloxylethyltrimellitate esters and acid anhydrides thereof and phosphate ester derivatives thereof so as to solve non-noble metal adhesion, however, adhesion to noble metals is insufficient. Among dental metals, noble metal alloys contain gold, platinum, palladium and silver as main components. The surface of these metals was usually subjected to tin plating or oxidation treatment in advance of bonding. However, this treatment was complicated and a sufficient adhesive force was not obtained.
Japanese Examined Patent Publication (Kokoku) No. 5-67146 reports that an adhesive force to a noble metal alloy can be improved similarly by applying a composition comprising a (meth)acrylate ester having a triazinethiol group and a volatile solvent on the surface, on which the noble metal is to be deposited, before applying an adhesive. However, adhesion to the non-noble metal alloy was found to be insufficient.
Japanese Unexamined Patent Publication (Kokai) No. 7-258248 proposes the use of a (meth)acrylate ester derivative having a disulfide cyclic group so as to solve noble metal adhesion. That is, a disulfide cyclic group-containing compound has a high adhesive force to noble metal and this technique using an adhesive composition comprising a (meth)acrylate ester derivative having a disulfide cyclic group and an organic solvent was expected to improve adhesion of an organic material to a noble metal alloy. However, the adhesive composition did not have enough adhesion to endure the severe intraoral environment and is also insufficient with respect to adhesion to a non-noble metal alloy.
Furthermore, Japanese Unexamined Patent Publication (Kokai) No. 9-67546 proposes a composition containing an acidic compound blended therein so as to enhance noble metal adhesion of the sulfur-containing triazine ring compound. Although a technique using the composition was expected to improve adhesion of an organic material to a non-noble metal and a noble metal alloy, water resistance was still insufficient. When partially damaged dental material is restored, it is sometimes unclear what kind of metal had been used. In such a case, a sufficient adhesive force may not be obtained if a proper kind of a surface treating agent (primer) is not used. For example, when a surface treating agent for a non-noble metal (primer) is used for a noble metal alloy or when a surface treating agent for a noble metal (primer) is used for a non-noble metal alloy, a sufficient adhesion cannot be obtained.
However, as described above, since silica-based, alumina-based, zirconia-based and metal-based materials are used in dental restorative materials, it was necessary to select and apply an adhesive material according to the adherend.
To solve these problems, adhesive materials containing both a silane coupling agent and an acid monomer have recently been marketed. However, since the silane coupling agent and the acid monomer cannot be stored in the same solvent for a long period, it was necessary to mix the two kinds of materials immediately before use.
There has been a need for materials which can be used regardless of the kind of adherend and which do not require a troublesome mixing operation before use.
Japanese Unexamined Patent Publication (Kokai) No. 63-51308 and Japanese Unexamined Patent Publication (Kokai) No. 7-277913 disclose dental adhesive compositions using a combination of a silane coupling agent and a phosphate ester monomer to bond a dental porcelain containing silicon dioxide with dental restorative materials such as a dental resin and a dental alloy.
However, since the silane coupling agent and the acid monomer do not readily coexist, it was necessary to mix them before use.
Japanese Unexamined Patent Publication (Kokai) No. 9-137129 discloses a dental adhesive composition comprising a coating solution containing a silane coupling agent and an acidic compound such as an organic carboxylic acid, and a coating material constituted by a polymerizable monomer which is applied on a surface on which the coating solution is to be applied, and which is polymerized in the presence of a polymerization catalyst. However, since this dental adhesive composition displays almost no adhesion to aluminum oxide or zirconium oxide, selective use with respect to the adherend was required.
Japanese Unexamined Patent Publication (Kokai) No. 2006-45179 discloses a dental adhesive composition for bonding a dental material composed of an inorganic compound or an organic composite containing an inorganic compound, and also proposes a dental adhesive composition having adhesion to aluminum oxide or zirconium oxide.
However, since a silane coupling agent is deteriorated by a phosphonic acid group-containing a (meth)acrylate-based monomer, it is difficult to stably exhibit the bonding effect for a long term. The silane coupling agent and an acid monomer do not readily and it was necessary to mix them before use.
Japanese Unexamined Patent Publication (Kokai) No. 2006-45094 describes a two-pack mixing type primer composition used for a pretreatment of the surface, on which a prosthesis made of a cured dental composite material is to be deposited, thereby improving adhesion before application of the adhesive material when the cured dental composite material is bonded with a dental material. However, this adhesive material has no adhesion to porcelain and has a primer composition which requires mixing of two liquids before bonding.
Japanese Unexamined Patent Publication (Kokai) No. 2000-248201 discloses a composition which exhibits sufficient adhesion to any of a base metal, a noble metal alloy and ceramics. However, when a silane coupling agent and an acidic group-containing polymerizable monomer are used as a one-pack type composition, serious defects with respect to storage stability of the one-pack type composition occurred.
Japanese Unexamined Patent Publication (Kokai) No. 2002-265312 discloses a technique using a composition which exhibits sufficient adhesion to any of dentin, a base metal alloy, a noble metal alloy and ceramics. However, when a silane coupling agent and an acidic group-containing polymerizable monomer are used as a one-pack type composition, serious defects with respect to storage stability of a one-pack type composition occurred.